Continuous heat treating machine



Nov. 12, 1935.

A. W. MACHLET CONTINUOUS HEAT TREATING MACHINE Filed Nov. 21, 1931 2 Sheets-Sheet 1 H mav l1" UI INV ENTOR mogul w'Maolzlat ATTORNEY Nov. 12, 1935. A. w. MACHLET CONTINUOUS HEAT TREATIN G MACHINE 2 Shets-Sheet 2 lNVENTOR w h Y E m N R m m A a mu 3 n3 Patented Nov. 12, 1935 UNITED STATES Y PATENT OFFICE 11 Claims.

This invention pertains to machines and methods for processing articles while subjected to heat in closed retorts inthe presence of treating materials.

One object of the invention is to provide an improved heat treating machine designed for a continuous cycle of operations including heating, treating and discharging the treated work.

Another object is to provide improved constructional arrangements and/or mechanical devices for such a machine. I

Another object is to provide improved combinations of instrumentalities in such a machine.

Another object is to provide an enclosed oscillating retort designed to receive work at one end, pass .the work through itself and discharge the work at the other end.

Another object is to provide means to prevent loss of treating material from such an enclosed oscillating conveyor. 7

Another object is to exclude air and other unwanted gases so as to produce the best possible product.

Another object isto agitate the work during its passage so as to expose all its surfaces, with substantial uniformity, to the treating material.

Other objects may be explained in the following detailed description of one form of the invention and may be pointed out in the appended claims.

Referring to the accompanying drawings:-

Fig. 1 is a longitudinal elevation, partly in vertical section of the body and left hand end of my improved continuous heat treating machine.

Fig. 2 is a similar elevation of the right hand end of the device of Fig. 1. However, in Fig. 2 the fragment of the body which is shown appears in full whereas it is in section in Fig. 1.

Fig. 3 is a horizontal section taken on the line 3-3 of Fig. 1.

Fig. 4 is a substantially vertical section taken on the line t'-t of Fig. 1.

The numeral i indicates a floor upon which is mounted a conventional frame 3, supporting a furnace 5, provided with a hot chamber 1, which may be heatedby any approved means. Chain her I is surrounded by brick insulation 9, secured in place in a conventional manner, and is of much. greater length than height or breadth. Chamber i contains a conventional oscillating refractorymetal, trough-like shelf II suspended by links I3 1 depending from the upper part of frame 3.

As shown best in Fig.1, pivot pins I5 and H in co-operation with links I3 permit shelf. ii to escillate a short distance both to the right and to the left from the indicated position.

Shelf II projects through an opening at the right hand end of chamber 1 and is provided, at the extension, with an iron strap I9 which, in the 5 indicated position, is shown .as loosely looped around an adjustable-bumper 2 I, of conventional type.

Shelf II is also provided with lugs 23 having a hole which contains a pivot pin 25. .Pin 25 passes loosely through an oval hole 21 in the upper end of a. rocker arm 29. The central portion of rocker arm 29 is pivoted at a shaft 3| journaled at frame 3.

Rocker arm 29 extends down from shaft 3| and terminates in a striking plate 33. In the position of Fig. 1 plate 33 engages a cam 35 which is tightly mounted on a shaft 31. Cam 35 and shaft 31 are designed to be rotated in the direction of arrow 38 by power, from any suitable source, not shown.

Upon shaft 3i there is tightly secured a lever arm 39, at the end of which is attached a tension spring M, designed to transmit torque through shaft 3i and rocker arm'29 to striking plate 33 and force it into contact with cam 35.

Thus member I I moves from the position of Fig, l,'to the right as shaft 3i is rotated 90. At 90 member 35 disengages member 33. As soon as the disengagement occurs spring M, acting through members 39, 29, 25, etc., moves member Ii to the left until the movement is abruptly halted by member I9 striking against member 2 I. Member I I carries a duct-like retort of sheet metal ma, which will be subsequently described in detail. Retort I M is rigidly but detachably secured to member II by strap clamps I03. When member I9 strikes member 2i, any work, for instance, the iron objects IM which are shown as loosely resting in retort Illi, slip, because of their momentum, a short distance to the'left 40 until brought to rest by friction with the bottom of member HM.

Upon a 180 further rotation of shaft iii, that is to say 270 beyond the position shown in Fig. 1, members 33 and 35 again engage. Members Ii, IM and I M are then again gradually moved to the right and the cycle is repeated.

Bumper 211 is rotatably mounted on a springmaintained bolt 22, so that it may be adjusted by the operator to vary the unrestrained movement of members as, 25, Ii, Iti, etc., as above described, thus varying the violence of the bumps between members it and 2t. and controllingthe average speed at which the work 8M travels to the. left.

ciprocating conveyor mechanism to distinguish it from the many well-known types of belt con- 1 veyors.

Referring to the right of Fig. 2, a chute I05, movably suspended at I06, is shown as attached to member II. A continuous stream of work may be loaded into the retort IOI from chute I 05. Retort IOI is provided with a sliding door I01, and chute I05 is provided with a sliding inspection door I09. Doors I01 and I09 are at a convenient height for an operator standing on fioor I. Chute I05 is loaded from a belt conveyor III, shown in Fig. 2, which is completely enclosed at II2 to a level considerably below the bottom of retort IOI so that treating gases which, because they are usually of lower specific gravity than air, will thus be prevented from leaking out of the retort IOI Door I01 is designed to completely close the right hand end of retort IOI when required, for instance, if the chute I05 is not in use; In such an event the work may be fed in through door I01 by hand. l l

The left hand end of retort IN is provided with a down spout II3 having a flexible portion II5 preferably provided with a suitable heat-resisting lining I II. A sliding door I I8 at the left hand end of retort IN is provided to permit the cleaning out of the retort IOI when required. The lower end of down spout I I3 is shown as discharging into a closed tank or box H9 where the work may be gradually accumulated after passing through retort IOI. Tank H9 may contain oil or water if it is desired to immediately quench or chill the work after it has passed through retort IOI as above described. I

It may be observed that both the bottom of down spout H3 and housing H2 are below retort I M so that we have in effect a bell-like closure or hood for the treating gases, which will prevent their wastage.

The treating materials may be either in the form of solids, powder, liquid or gas, but treating materials in gaseous form are generally used, and the fittings at the left of retort I01 are particularly arranged for the introduction of gaseous treating materials into retort IOI.

The method of treating work, usually small ferrous articles, in the above described apparatus, which is especially adapted for operation in combination with said apparatus, consists of combined nitrogenizing and carburizing :at a retort temperature of 1300" to 1600 Fahrenheit. Suitable treating materials include any hydrocarbon gas, which may enter through a pipe 20I, and ammonia gas, which may enter through a pipe 203. Pipes 20I and 203 communicate through a pipe 205 with the left hand end of retort IOI.

Retort IN is stiffened at its upper portion by diagonal braces I02, and. these braces also act as baflles for the even distribution of the treating gases as they flow toward the right through the retort IOI.

With the above described combination of apparatus and method, small ferrous articles can be hardened sufficiently for most practical purposes, at very low cost, in about five minutes of actual processing in the retort ml. The articles are discharged from the retort IOI, ready for use as soon as they cool ofi.

The apparatus and method above described is particularly designed to perform the same type of hardening of ferrous articles which is now usually effected in cyaniding furnaces and to accomplish this work without the danger to the health of the operator such 'as is always present 5 when cyanide is used;

Such a surface need not be very thick and by combining the carburizing and nitrogenizing treating materials as above described a coating of adequate hardness and which requires no tem- 10 pering as does a carburized case, may be produced as a continuous operation by the above described apparatus and method.

I do not limit myself to the exact construction or method shown and described above, which 15 may be modified in accordance with progress of the art and the scope of my invention will be pointed out in the following claims.

I claim:

1. A heat processing machine including an 20 oscillatory retort designed to confine treating material when in a gaseous state, closed at top, bottom and sides, mounted in a substantially horizontal plane so as to prevent thermo siphon draft and loss of such gas, means to jar the re- 25 tort in one direction of its length and permit it to return the distance jarred more gradually so as to advance work contained in the retort a step at a time and means to close at least one end of the retort to cooperate with the horizontal 30 mounting in minimizing the loss of the treating material while in the gaseous state.

2. A heat processing machine including an oscillatory retort designed to confine treating material when in a gaseous state, closed at top, bot- 30 tom and sides, mounted in a substantially horizontal plane so as to prevent thermo siphon draft and loss of such gas, means to jar the retort in one direction of its lengthand permit it to return the distance jarred more gradually so 40' as to advance work contained in the retort a step at a time and means to close both ends of the retort to cooperate with the horizontal mounting in minimizing the loss of the treating material while in the gaseous state. 45

3. A heat processing machine including an oscillatory retort designed to confine treating material when in a gaseous state, closed at top, bottom and sides, mounted in a substantially horizontal plane so as to prevent thermo siphon 59 draft and loss of such gas, means to jar the retort in one direction of its length and permit it to return the distance jarred more gradually so as to advance work contained in the retort a step at a time, a spout at one end of the retort 55 and closure means at the lower end thereof designed to be closed while the machine is operating to cooperatewith the horizontal mounting in minimizing the loss of the treating material while in the gaseous state.

4. A heat processing machine including an oscillatory retort designed to confine treating material when in a gaseous state, closed at top, bottom and sides, mounted in a substantially horizontal plane so as tov prevent thermo siphon draft and loss of such gas, means to jar the retort in one direction of its length and permit it to return the distance jarred more gradually so one directionbf its length and permit it to return the distance jarred more gradually so as to advance work contained in the retort a step at a time.

6. A heat processing machine including an oscillatory ductlike retort provided with a chute atone end, a tubular projection from substantially the junction of the retort and chute, and a flexible tubular means connected to the other end of the projection for the introduction of treating material intov the retort while it is in vibration and without wastage of treating materlal when in'a gaseous state.

7. A heat processing machine including an os-. cillatory ductlike retort provided with a chute at one end, a flexibleextension for the chute and a substantially air and gas-tight stationary receptacle at the bottom of the chute, whereby treating material while in a gaseous state may be conserved and the retort be substantially unconstrained so that it may vibrate freely.

8. A heat processing machine including an oscillatory ductlike retort, a mounting therefor to support same in a substantially horizontal position so as to avoid the formation of a thermoone end, a tubular projection from substantially the junction of the retort and chute, and a flexible tubular means connected to the other end of the projection for the introduction of treating material into the retort whileit is in vibration and without wastage of treating material when in a gaseous state.

9. A heat processing machine including an oscillatory ductlike retort, a mounting therefor to support some in a substantially horizontal position so as to avoid the formation of a thermosiphon draft therein, provided with a' chute at 5 one end, a flexible extension for the chute and a substantially air and gas-tight stationary receptacle at the bottom of the chute, whereby treating material while in a gaseous-state may be conserved and the retort be substantially unconstrained so that it may vibrate freely.

10. A heat processing machine including an oscillatory ductlike retort provided with a chute at one end, a flexible extension for the chute and a substantially air and gas-tight stationary receptacle at the bottom of the chute, whereby treating material while in a gaseous state may be conserved and the retort be substantially unconstrained so that it may vibrate freely, a tubular projection from substantially thejunction of 20 the retort and chute and a flexible tubular means connected to the other end of the projection for the introduction of treating material while the I retort is in vibration and without wastage of treating material when in a gaseous state.

11. A heat processing machine including an oscillatory ductlike retort, a. mounting therefor to support same in a substantially horizontal position so as to avoid the formation of a thermosiphon draft therein, a flexible extension for the chute and a substantially air and gas-tight Stationary receptacle at the bottom .of the chute, whereby treating, material while in a gaseous state may be conserved and the retort be substantially unconstrained so that it may vibrate freely, a tubular projection from substantially siphon draft therein, provided with a chute at the junction of the retort and chute and a flexible tubular means connected to the other end of the projection for the introduction of treating material while the retort is in vibration and without wastage of treating material when in a gaseous state.

' ADOLPH W. MACHLET. 

